Psychedelics have sparked interest as potential treatments for social cognition deficits commonly associated with the autism spectrum and social anxiety. Previous studies have shown that psychedelics modulate social processing by altering emotion recognition in facial expressions, joint attention in social interactions, perspective-taking, and empathy. The evidence suggests that the effect may be linked to their impact on social cognition networks. However, the exact mechanisms underlying this impact remain poorly understood. The research team led by Miguel Castelo-Branco conducted a pharmacological study investigating the effects of N,N-Dimethyltryptamine (psychedelic DMT) on functional connectivity in brain regions relevant to social cognition, using a within-subject design. The results supported the hypothesis that DMT induces changes in functional connectivity in brain regions relevant to social cognition, as well as in areas associated with emotion and affective value. Furthermore, changes in connectivity strength were correlated with increases in self-reported psychedelic effects. These correlations highlight the relationship between DMT’s neural effects on socioemotional circuits and subjective experiences. These findings offer insights into the effects of psychedelics on social behaviour, with implications for disorders like social anxiety and depression. Simultaneously, they suggest that increased connectivity, rather than reduced activity, plays a crucial role in psychedelic states. Thus, these results advance our understanding of the therapeutic potential of psychedelics and their effects on the "social brain". This study was supported by the BIAL Foundation, in the scope of the research project 252/18 - Spiritual states induced by ayahuasca, and the involvement of the reward system, and published in Frontiers in Pharmacology, in the article Increased functional connectivity between brain regions involved in social cognition, emotion and affective-value in psychedelic states induced by N,N-Dimethyltryptamine (DMT).
ABSTRACT
The modulation of social cognition is suggested as a possible mechanism contributing to the potential clinical efficacy of psychedelics in disorders involving socio-emotional and reward processing deficits. Resting-state functional Magnetic Resonance Imaging (rs-fMRI) can be used to detect changes in brain connectivity during psychedelic-induced states. Thus, this pharmacoimaging study investigates the effects of N,N-Dimethyltryptamine (DMT) on functional connectivity in brain areas relevant to social cognition, using a within-subject design in eleven healthy experienced users. The study included both an active and a control condition, conducted at different time points. The active condition involved DMT inhalation, while the control condition did not. Seed-based connectivity was measured for the two core regions involved in theory of mind and emotional processing, respectively, the posterior supramarginal gyrus and the amygdala. DMT increased supramarginal gyrus connectivity with the precuneus, posterior cingulate gyrus, amygdala, and orbitofrontal cortex. Additionally, increased connectivity emerged between the amygdala and orbitofrontal cortex. These results demonstrate that DMT modulates brain connectivity in socio-emotional and affective-value circuits, advancing our understanding of the neural mechanisms underlying the psychedelic experience and its potential therapeutic action.
